There were 43 executions this year, down from 46 last year and 85 in 2000. Some 78 prisoners were added to the population of death rows – the first time since the death penalty was reintroduced in 1976 that new sentences have dropped below the 100 mark. Last year 112 people were sentenced to death, and 224 in 2000.

"The multitude of problems associated with the death penalty is gradually convincing Americans that it can no longer be sustained," concludes Richard Dieter, the director of the information centre.

While the application of the death penalty fell, America's tolerance of it also declined. The highlight of the year was the execution of Troy Davis in Georgia in September that saw an outpouring of disgust and outrage at an intensity rarely seen within the country.

Davis was put to death by lethal injection on 21 September amid widespread warnings that his conviction had been unsafe. Several of the witnesses who put him on death row in 1991 for the murder of an off-duty police officer in Savannah had since recanted, leading to the mantra of Davis's supporters: "Too much doubt."

Georgia's dogged determination to carry out the execution despite the questions surrounding the case led to protests from around the world, including interventions by the Pope, Jimmy Carter, a former head of the FBI and several Georgia judges.

Unease about this individual case was echoed by a growing mood of distaste towards the death penalty across America. Polls showed that only 61% supported the death sentence, down from 80% in 1994.

At a state level, Illinois joined New Mexico, New Jersey and New York to become the fourth state in as many years to abandon the practice. "Our system of imposing the death penalty is inherently flawed. It is impossible to devise a system that is consistent, free of discrimination, and that always gets it right," said Pat Quinn, governor of Illinois, as he signed the abolition bill into law in March.

The governor of Oregon, John Kitzhaber, declared in November that there would not be any more executions under his watch.

But 34 states still have capital punishment on their books. Among them, the south remains the heart of the death penalty in the US. Three southern states – Texas, Virginia and Oklahoma – account for more than half of the total of 1,277 executions that have been carried out since 1976. Texas alone has carried out 37% of them.

The death penalty may be declining in its use but America continues to be saddled with an enormous problem relating to its historical popularity. At its peak almost 300 people were put on death row every year in the 1990s and many of them are still sitting there: altogether, 3,251 men and women remain on death row, draining states of scarce resources and putting an extreme strain on the judicial system.